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Abstract:

A plastic package includes a plurality of terminal members each having an
outer terminal, an inner terminal, and a connecting part connecting the
outer and the inner terminal; a semiconductor device provided with
terminal pads connected to the inner terminals with bond wires; and a
resin molding sealing the terminal members, the semiconductor device and
the bond wires therein. The inner terminals of the terminal members are
thinner than the outer terminals and have contact surfaces. The upper,
the lower and the outer side surfaces of the outer terminals, and the
lower surfaces of the semiconductor device are exposed outside. The inner
terminals, the bond wires, the semiconductor device and the resin molding
are included in the thickness of the outer terminals.

Claims:

1. A plastic package fabricating method comprising the steps of:forming a
processed sheet having at least one pair of terminal members connected to
each other through a connection, each having an outer terminal, an inner
terminal and a connecting part connecting the outer and the inner
terminal by subjecting a terminal forming sheet to a half-etching
process;attaching the processed sheet to a semiconductor device
supporting tape with a surface thereof opposite a half-etched surface in
contact with the semiconductor device supporting tape, and attaching a
semiconductor device to the semiconductor device supporting
tape;connecting the inner terminals of the terminal members of the
processed sheet to the semiconductor device with bond wires;sealing the
processed sheet and the semiconductor device held between a pair of flat
molding plates in a resin molding by a molding process; andfinishing a
plastic package by removing the pair of flat molding plates and the
semiconductor device supporting tape from the resin molding, attaching a
cutting tape to the resin molding, and cutting parts, corresponding to
the connection of the processed sheet, of the resin molding from a side
opposite the side of the cutting tape.

5. A stacked plastic package formed by stacking a plurality of plastic
packages each comprising:a plurality of terminal members each having an
outer terminal having an upper surface, a lower surface and an outer side
surface, an inner terminal having a contact surface, and a connecting
part connecting the outer and the inner terminal;a semiconductor device
provided with terminal pads connected to the contact surfaces of the
inner terminals with bond wires; anda resin molding sealing the terminal
members, the semiconductor device and the bond wires therein;wherein the
inner terminals of the terminal members are thinner than the outer
terminals and have the contact surfaces,the contact surfaces of the inner
terminals, the upper surfaces of the outer terminals, the lower surfaces
of the outer terminals of the terminal members are included in planes,
respectively, andthe upper, the lower and the outer side surfaces of the
outer terminals of the terminal members, and a surface of the
semiconductor device opposite the surface provided with the terminal pads
are exposed outside, and the inner terminals, the bond wires, the
semiconductor device and the resin molding are included in the thickness
of the outer terminals.

6. The stacked plastic package according to claim 5, whereinthe lower
surfaces of the outer terminals of the plastic package are connected
electrically to the upper surfaces of the outer terminals of the plastic
package underlying the former.

7. The stacked plastic package according to claim 5, whereinthe plurality
of plastic packages are arranged in a plurality of rows and stacked up in
a plurality of layers.

8. The stacked, plastic package according to claim 7, whereinthe outer
side surfaces of the respective outer terminals of the laterally adjacent
plastic packages are connected electrically.

9. A plastic package comprising:a plurality of terminal members each
having an outer terminal having an upper surface, a lower surface and an
outer side surface, and leads including inner terminals each having an
upper surface and a lower surface;a semiconductor device supported by the
leads and provided with terminal pads connected to the inner terminals
with bond wires; anda resin package sealing the terminal members, the
semiconductor device and the bond wires therein;wherein the inner
terminals of the terminal members are thinner than the outer terminals,
have the upper and the lower surfaces, and are included in the thickness
of the outer terminals,the upper and the lower surfaces of the inner
terminals and the upper and the lower surfaces of the outer terminals of
the terminal members are included in planes, respectively, andthe lower
and the outer side surfaces of the outer terminals of the terminal
members are exposed outside.

10. The plastic package according to claim 9, whereinthe semiconductor
device is of a center-pad type, and the leads are connected to a
peripheral part of the semiconductor device.

11. The plastic package according to claim 9, whereinan additional
semiconductor device provided with terminal pads connected to the inner
terminals with bond wires is put on the semiconductor device.

12. The plastic package according to claim 9 whereinthe package is formed
in a flat and square shape.

13. The plastic package according to claim 9 whereinthe upper surfaces of
the outer terminals of each terminal member are partly exposed.

14. The plastic package according to claim 9, whereincut parts are formed
in the outer surfaces of the outer terminals of the terminal members,
respectively.

15. The plastic package according to claim 9, whereinterminal members are
formed of Cu, a Cu-base alloy or a Fe--Ni alloy containing 42% Ni.

16. The plastic package according to claim 9, whereinthe respective upper
and lower surfaces of the inner terminals and the outer terminals of the
terminal members are coated with a plated metal layer selected from a
plated solder layer, a plated gold layer, a plated silver layer, a plated
palladium layer and a plated tin layer.

17. A plastic package fabricating method comprising the steps of:forming a
processed sheet having at least one pair of terminal members connected to
each other through a connection, each having an outer terminal, a lead
including an inner terminal by subjecting a terminal forming sheet to a
half-etching process;mounting a semiconductor device on the leads of the
terminal members of the processed sheet;connecting the inner terminals of
the terminal members of the processed sheet to the semiconductor device
with bond wires;attaching a molding tape to a half-etched surface of the
processed sheet and sealing the processed sheet and the semiconductor
device in a resin molding by molding; andfinishing a plastic package by
removing the molding tape from the resin molding, attaching a cutting
tape to the resin molding, and cutting parts, corresponding to the
connection of the processed sheet, of the resin molding from a side
opposite the side of the cutting tape.

18. The plastic package fabricating method according to claim 17,
whereinthe processed sheet and the semiconductor device are held between
a pair of flat plates for molding to seal the processed sheet and the
semiconductor device in the resin molding.

19. The plastic package fabricating method according to claim 17,
whereinthe processed sheet and the semiconductor device are enclosed in a
space defined by a flat plate and a predetermined mold for molding to
seal the processed sheet and the semiconductor device in the resin
molding.

20. A plastic package comprising:a plurality of terminal members each
having an outer terminal having upper, lower and outer side surfaces, and
a lead including an inner terminal having a contact surface;a die pad
connected to the terminal members;a semiconductor device mounted on the
die pad, and provided with terminal pads connected to the contact
surfaces of the inner terminals with bond wires; anda resin molding
sealing the terminal members, the die pad, the semiconductor device and
the bond wires therein;wherein the inner terminal of each of the terminal
members is thinner than the outer terminal, and has the contact surface,
and included in the thickness of the outer terminal, the contact surfaces
of the inner terminals and the upper and lower surfaces of the outer
terminals of the terminal members are included in planes, respectively,
the outer side surfaces of the outer terminals of the terminal members,
and the lower surfaces of the leads are exposed outside.

21. The plastic package according to claim 20, whereinthe upper surfaces
of the outer terminals of the terminal members and the mounting surface
of the die pad are included in a plane.

22. The plastic package according to claim 20, whereinan additional
semiconductor device provided with terminal pads connected to the inner
terminals with bond wires is put on the semiconductor device.

23. The plastic package according to claim 20 whereinthe package is formed
in a flat, square shape.

24. The plastic package according to claim 20, whereinthe upper surfaces
of the outer terminals of the terminal members are partially exposed.

25. The plastic package according to claim 20, whereinthe outer terminals
of the terminal members are provided with cut parts in their outer side
surfaces, respectively.

26. The plastic package according to claim 20, whereinthe terminal members
are formed of Cu, a Cu-base alloy or a Fe--Ni alloy containing 42% Ni.

27. The plastic package according to claim 20, whereinthe contact surfaces
of the inner terminals and the upper and lower surfaces of the outer
terminals of the terminal members are coated with a plated metal layer as
a bonding plated layer selected from a plated solder layer, a plated gold
layer, a plated silver layer, a plated palladium layer and a plated tin
layer.

28. A plastic package fabricating method comprising the steps of:forming a
processed sheet having at least one pair of terminal members connected to
each other through a connection, each having an outer terminal, a lead
including an inner terminal, and a die pad by subjecting a terminal
forming sheet to half-etching;mounting a semiconductor device on the die
pad;connecting the inner terminals of the terminal members of the
processed sheet to the semiconductor device with bond wires;attaching a
molding tape to the processed sheet, and sealing the processed sheet and
the semiconductor device in a resin molding by molding; andfinishing a
plastic package by removing the molding tape from the resin molding,
attaching a cutting tape to the resin molding and cutting parts,
corresponding to the connection of the processed sheet, of the resin
molding from a side opposite the side of the cutting tape.

29. The plastic package fabricating method according to claim 28,
whereinthe processed sheet and the semiconductor device are held between
a pair of flat plates for molding to seal the processed sheet and the
semiconductor device in the resin molding.

30. The plastic package fabricating method according to claim 28,
whereinthe processed sheet and the semiconductor device are enclosed in a
space defined by a flat plate and a predetermined mold for molding to
seal the processed sheet and the semiconductor device in the resin
molding.

Description:

[0001]This is a Division of application Ser. No. 10/821,173 filed Apr. 9,
2004. The disclosure of the prior application is hereby incorporated by
reference herein in its entirety.

TECHNICAL FIELD

[0002]The present invention relates to a small, thin plastic package, a
stacked plastic package built by stacking small, thin plastic packages,
and a method of fabricating such plastic packages.

BACKGROUND ART

[0003]High-density packaging of semiconductor devices for electronic
appliances has been desired for downsizing electronic appliances.
Miniaturization and thickness reduction of semiconductor parts have
progressed, and packages that enable further thickness reduction and cost
reduction are demanded.

[0004]Under such circumstances, techniques have been proposed to cope with
thickness reduction. A plastic package proposed in JP 11-307675 A has a
lead frame having exposed upper and lower surfaces. A plastic package
proposed in JP 11-260989 has leads including those which are exposed and
used as outer terminals.

[0005]On the other hand, efforts are being made to achieve one-chip system
LSI. Two-dimensional wiring limits increasing operating speed by
shortening wiring lines, and the development of techniques to achieve
one-chip system LSI requires high development costs and long development
time. Recently, trials have been made to achieve system LSI by using
packages built up by stacking semiconductor devices for three-dimensional
arrangement.

[0006]Such packages are called also system packages.

[0007]A stacked, plastic package disclosed in JP 11-307675 A is built by
stacking plastic packages, and leads each having exposed upper and lower
surfaces are used for electrical connection. However, those plastic
packages are provided with a die pad and hence it is difficult to reduce
the thickness of those plastic packages.

[0008]The plastic package mentioned in JP 11-260989 A cannot be formed in
a stacked structure.

[0009]A package disclosed in JP 2002-33434 A is formed by stacking
semiconductor devices (chips) and sealing the stacked semiconductor
devices in a package. This package has low application flexibility and is
difficult to apply to general purposes.

[0010]JP 11-307675 A

[0011]JP 11-260989 A

[0012]JP 2002-33434 A

[0013]Thus, semiconductor parts have been progressively miniaturized and
made thinner, and still thinner packages have been demanded. Efforts have
been made to fabricate system packages, to construct a system package by
stacking a plurality of plastic packages, but further thickness reduction
of the plastic packages is necessary.

DISCLOSURE OF THE INVENTION

[0014]The present invention has been made to meet the foregoing
requirements and it is therefore an object of the present invention to
provide a package capable of further reducing the thickness of a
semiconductor device at a low cost. More concretely, the present
invention provides a stacked, plastic package realizing a stacked system
package built by stacking a plurality of plastic packages. Thus, the
present invention provides an easily mass-producible plastic package.

[0015]Another object of the present invention is to provide an easily
mass-producible semiconductor device suitable for achieving the further
reduction of the thickness of a semiconductor part at a low cost. A third
object of the present invention is to provide a stacked plastic package
built by stacking such thin plastic packages and realizing the so-called
stacked system package.

[0016]A fourth object of the present invention is to provide a method of
fabricating such a thin plastic package.

[0017]A plastic package according to the present invention includes: a
plurality of terminal members each having an outer terminal having an
upper surface, a lower surface and an outer side surface, an inner
terminal having a contact surface, and a connecting part connecting the
outer and the inner terminal; a semiconductor device provided with
terminal pads connected to the contact surfaces of the inner terminals
with bond wires; and a resin molding sealing the terminal members, the
semiconductor device and the bond wires therein; wherein the inner
terminals of the terminal members are thinner than the outer terminals
and have the contact surfaces, the contact surfaces of the inner
terminals, the upper surfaces of the outer terminals, the lower surfaces
of the outer terminals of the terminal members are included in planes,
respectively, and the upper, the lower and the outer side surfaces of the
outer terminals of the terminal members, and a surface of the
semiconductor device opposite the surface provided with the terminal pads
are exposed outside, and the inner terminals, the bond wires, the
semiconductor device and the resin molding are included in the thickness
of the outer terminals.

[0018]In the plastic package according to the present invention, the outer
terminal of each terminal member has a cut part on the outer side
surface.

[0019]In the plastic package according to the present invention, each
terminal member is formed of Cu, a Cu-base alloy or a Fe--Ni alloy
containing 42% Ni.

[0020]In the plastic package according to the present invention, the
contact surfaces of the inner terminals, and the upper and the lower
surfaces of the outer terminals of the terminal members are coated with a
plated metal layer selected from a plated solder layer, a plated gold
layer, a plated silver layer, a plated palladium layer and a plated tin
layer.

[0021]A plastic package fabricating method according to the present
invention includes the steps of: forming a processed sheet having at
least one pair of terminal members connected to each other through a
connection, each having an outer terminal, an inner terminal and a
connecting part connecting the outer and the inner terminal by subjecting
a terminal forming sheet to a half-etching process; attaching the
processed sheet to a semiconductor device supporting tape with a surface
thereof opposite a half-etched surface in contact with the semiconductor
device supporting tape, and attaching a semiconductor device to the
semiconductor device supporting tape; connecting the inner terminals of
the terminal members of the processed sheet to the semiconductor device
with bond wires; sealing the processed sheet and the semiconductor device
held between a pair of flat molding plates in a resin molding by a
molding process; and finishing a plastic package by removing the pair of
flat molding plates and the semiconductor device supporting tape from the
resin molding, attaching a cutting tape to the resin molding, and cutting
parts, corresponding to the connection of the processed sheet, of the
resin molding from a side opposite the side of the cutting tape.

[0022]In the plastic package fabricating method according to the present
invention, the semiconductor device supporting tape is a flat suction
plate.

[0023]In the plastic package fabricating method according to the present
invention, the flat suction plate is provided with suction holes arranged
in its entire surface.

[0024]In the plastic package fabricating method according to the present
invention, the semiconductor device supporting tape is a molding tape.

[0025]According to the present invention, a stacked plastic package is
formed by stacking a plurality of plastic packages each including: a
plurality of terminal members each having an outer terminal having an
upper surface, a lower surface and an outer side surface, an inner
terminal having a contact surface, and a connecting part connecting the
outer and the inner terminal; a semiconductor device provided with
terminal pads connected to the contact surfaces of the inner terminals
with bond wires; and a resin molding sealing the terminal members, the
semiconductor device and the bond wires therein; wherein the inner
terminals of the terminal members are thinner than the outer terminals
and have the contact surfaces, the contact surfaces of the inner
terminals, the upper surfaces of the outer terminals, the lower surfaces
of the outer terminals of the terminal members are included in planes,
respectively, and the upper, the lower and the outer side surfaces of the
outer terminals of the terminal members, and a surface of the
semiconductor device opposite the surface provided with the terminal pads
are exposed outside, and the inner terminals, the bond wires, the
semiconductor device and the resin molding are included in the thickness
of the outer terminals.

[0026]In the stacked plastic package according to the present invention,
the lower surfaces of the outer terminals of the plastic package are
connected electrically to the upper surfaces of the outer terminals of
the plastic package underlying the former.

[0027]In the stacked plastic package according to the present invention,
the plurality of plastic packages are arranged in a plurality of rows and
stacked up in a plurality of layers.

[0028]In the stacked plastic package according to the present invention,
the outer surfaces of the respective outer terminals of the laterally
adjacent plastic packages are connected electrically.

[0029]The plastic package of the present invention is capable of further
reducing the thickness of semiconductor parts at a low cost.
Particularly, the present invention provides an efficiently
mass-producible thin plastic package suitable for forming a stacked
system package.

[0030]Thus, a stacked plastic package to realize a stacked system package
can be provided.

[0031]A structure not provided with any die pad is formed by combining the
terminal members formed by a half-etching process and having the outer
terminals each having at least a thick portion of a thickness equal to
that of the terminal forming sheet and the thin inner terminals thinned
by half-etching, and the semiconductor device of a thickness smaller than
that of the terminal forming sheet so that the surface, not provided with
terminal pads, of the semiconductor device is exposed. Thus, the
reduction of the thickness can be achieved by sealing the component parts
including the thin semiconductor device in a space of a thickness not
greater than that of the terminal forming sheet.

[0032]More concretely, the contact surfaces of the inner terminals of the
terminal members are formed by half-etching, and the terminal members are
extended in the same direction such that the upper and the lower surfaces
of the outer terminals, and the contact surfaces of the inner terminals
are included in planes, respectively, and the inner terminals extend
inward. The upper, the lower and the outer side surfaces of the outer
terminals serving as contact surfaces are exposed. The semiconductor
device is not mounted on a die pad and is sealed in the resin molding
such that the semiconductor device is spaced from the inner terminals of
the terminal members, the terminal surface of the semiconductor device
provided with the terminal pads faces the same direction as the
half-etched surfaces of the terminal members, the lower surface of the
semiconductor device opposite the terminal surface is flush with the
surface opposite the half-etched surface of the terminal members, and the
lower surface of the semiconductor device is exposed.

[0033]Wire bonding for connecting the terminal pads of the semiconductor
device to the inner terminals facilitates connecting work and ensures the
reliability of connection.

[0034]The plastic package can be efficiently mass-produced by a plastic
package fabricating method of a multiple-chip fabricating system
according to the present invention.

[0035]Cut parts formed in the outer side surfaces of the outer terminals
facilitate separating plastic packages by dicing.

[0036]The molding step does not need any mold provided with cavities of a
special shape. Semiconductor devices can be simultaneously sealed in a
resin molding by holding a semiconductor device assembly between flat
plates during molding. Such a molding step is suitable for mass
production and is desirable from the viewpoint of equipment.

[0037]Terminal members are formed of Cu, a Cu-base alloy, or a Fe--Ni
alloy containing 42% Ni.

[0038]The contact surfaces of the inner terminals, and the upper and the
lower surfaces of the outer terminals of the terminal members are coated
with a plated metal layer chosen from a plated solder layer, a plated
gold layer, a plated silver layer, a plated palladium layer and a plated
tin layer. The plated metal layer ensures reliable connection by wire
bonding.

[0039]Since the lower surface not provided with any terminal pads of the
semiconductor device is exposed, and the plastic package is not provided
with any die pad, a resin molding covering the semiconductor device can
be formed in an increased thickness, which facilitates assembly and
enhances the heat dissipating ability of the plastic package.

[0040]The plastic package fabricating method according to the present
invention is capable of efficiently mass-producing the thin, plastic
packages of the present invention.

[0041]The stacked plastic package of the present invention constructed by
stacking the plastic packages realizes a system package.

[0042]A plastic package according to the present invention includes: a
plurality of terminal members each having an outer terminal having an
upper surface, a lower surface and an outer side surface, and leads
including inner terminals each having an upper surface and a lower
surface; a semiconductor device supported by the leads and provided with
terminal pads connected to the inner terminals with bond wires; and a
resin package sealing the terminal members, the semiconductor device and
the bond wires therein; wherein the inner terminals of the terminal
members are thinner than the outer terminals, have the upper and the
lower surfaces, and are included in the thickness of the outer terminals,
the upper and the lower surfaces of the inner terminals and the upper and
the lower surfaces of the outer terminals of the terminal members are
included in planes, respectively, and the lower and the outer side
surfaces of the outer terminals of the terminal members are exposed
outside.

[0043]In the plastic package according to the present invention, the
semiconductor device is of a center-pad type, and the leads are connected
to a peripheral part of the semiconductor device.

[0044]In the plastic package according to the present invention, an
additional semiconductor device provided with terminal pads connected to
the inner terminals with bond wires is put on the semiconductor device.

[0045]The plastic package according to the present invention, wherein the
package is formed in a flat, square shape.

[0046]In the plastic package according to the present invention, the upper
surfaces of the outer terminals of each terminal member are partially
exposed.

[0047]In the plastic package according to the present invention, cut parts
are formed in the outer surfaces of the outer terminals of the terminal
members, respectively.

[0048]In the plastic package according to the present invention, terminal
members are formed of Cu, a Cu-base alloy or a Fe--Ni alloy containing
42% Ni.

[0049]In the plastic package according to the present invention, the upper
and lower surfaces of the inner and the outer terminals of terminal
members are coated with a plated metal layer selected from a plated
solder layer, a plated gold layer, a plated silver layer, a plated
palladium layer and a plated tin layer.

[0050]According to the present invention, a plastic package fabricating
method includes the steps of: forming a processed sheet having at least
one pair of terminal members connected to each other through a
connection, each having an outer terminal, a lead including an inner
terminal by subjecting a terminal forming sheet to a half-etching
process; mounting a semiconductor device on the leads of the terminal
members of the processed sheet; connecting the inner terminals of the
terminal members of the processed sheet to the semiconductor device with
bond wires; attaching a molding tape to a half-etched surface of the
processed sheet and sealing the processed sheet and the semiconductor
device in a resin molding by molding; and finishing a plastic package by
removing the molding tape from the resin molding, attaching a cutting
tape to the resin molding, and cutting parts, corresponding to the
connection of the processed sheet, of the resin molding from a side
opposite the side of the cutting tape.

[0051]In the plastic package fabricating method according to the present
invention, the processed sheet and the semiconductor device are held
between a pair of flat plates for molding to seal the processed sheet and
the semiconductor device in the resin molding.

[0052]In the plastic package fabricating method according to the present
invention, the processed sheet and the semiconductor device are enclosed
in a space defined by a flat plate and a predetermined mold for molding
to seal the processed sheet and the semiconductor device in the resin
molding.

[0053]The plastic package of the present invention achieves the further
miniaturization and thickness reduction of semiconductor parts at a low
cost, and enables the efficient mass-production of QFN packages or SON
packages.

[0054]The processed sheet is formed by a half-etching process and at least
a thick portion of each of the outer terminals has a thickness equal to
that of the terminal forming sheet. The terminal members include the
outer terminals, and the leads including the inner terminals and formed
integrally with the outer terminals, respectively. The terminal members
are extended in the same direction such that the upper and lower surfaces
of the outer terminals, and the contact surfaces of the inner terminals
are included in planes, respectively. The terminal members are arranged
near the semiconductor device with the outer terminals extending outward
and the inner terminals extending inward. The plastic package has LOC
construction (lead-on-chip construction), in which the lead of each
terminal member lies around the terminal surface of the semiconductor
device, or COL construction (chip-on-lead construction), in which the
semiconductor device is mounted on the leads of the terminal members. The
lower surface and the outer side surface of the thick part of each outer
terminal on the side of the half-etched surface of each terminal member
are exposed contact surfaces, the surfaces of the outer terminals of the
terminal members are exposed partly, and the rest of the parts of the
plastic package are sealed in the resin molding.

[0055]Wire bonding for connecting the terminal pads of the semiconductor
device to the inner terminals facilitates connecting work and ensures the
reliability of connection.

[0056]The plastic package can be efficiently mass-produced by a plastic
package fabricating method of a multiple-chip fabricating system
according to the present invention.

[0057]The lower and the outer side surface of the thick part of the outer
terminal on the side of the half-etched surface of each terminal member
having a generally flat, square shape are exposed contact surfaces, and
the rest of the parts of the plastic package are sealed in the resin
molding. Thus, the plastic package can be sealed in the resin molding
without using any special mold during molding. The construction of the
plastic package is satisfactory from the viewpoint of mass production and
equipment.

[0058]The semiconductor device of a center-pad type for the LOC
construction enables further thickness reduction.

[0059]Cut parts formed in the outer side surfaces of the outer terminals
facilitate separating plastic packages by dicing.

[0060]Terminal members are formed of Cu, a Cu-base alloy, or a Fe--Ni
alloy containing 42% Ni.

[0061]The contact surfaces of the inner terminals and the upper and lower
surfaces of the outer terminals of each terminal member are coated with a
plated metal layer chosen from a plated solder layer, a plated gold
layer, a plated silver layer, a plated palladium layer and a plated tin
layer. The plated metal layer ensures reliable connection by wire
bonding.

[0064]A plastic package according to the present invention includes: a
plurality of terminal members each having an outer terminal having upper,
lower and outer side surfaces, and a lead including an inner terminal
having a contact surface; a die pad connected to the terminal members; a
semiconductor device mounted on the die pad, and provided with terminal
pads connected to the contact surfaces of the inner terminals with bond
wires; and a resin molding sealing the terminal members, the die pad, the
semiconductor device and the bond wires therein; wherein the inner
terminal of each of the terminal members is thinner than the outer
terminal, and has the contact surface, and included in the thickness of
the outer terminal, the contact surfaces of the inner terminals and the
upper and lower surfaces of the outer terminals of the terminal members
are included in planes, respectively, the outer side surfaces of the
outer terminals of the terminal members, and the lower surfaces of the
leads are exposed outside.

[0065]In the plastic package according to the present invention, the upper
surfaces of the outer terminals of the terminal members and the mounting
surface of the die pad are included in a plane.

[0066]In the plastic package according to the present invention, an
additional semiconductor device provided with terminal pads connected to
the inner terminals with bond wires is put on the semiconductor device.

[0067]The plastic package is formed in a flat, square shape.

[0068]In the plastic package according to the present invention, the upper
surfaces of the outer terminals of the terminal member are partially
exposed.

[0069]In the plastic package according to the present invention, the outer
terminals of the terminal members are provided with cut parts in their
outer side surfaces, respectively.

[0070]In the plastic package according to the present invention, the
terminal members are formed of Cu, a Cu-base alloy or a Fe--Ni alloy
containing 42% Ni.

[0071]In the plastic package according to the present invention, the
contact surfaces of the inner terminals and the upper and lower surfaces
of the outer terminals of the terminal members are coated with a plated
metal layer as a bonding plated layer selected from a plated solder
layer, a plated gold layer, a plated silver layer, a plated palladium
layer and a plated tin layer.

[0072]A plastic package fabricating method according to the present
invention includes the steps of: forming a processed sheet having at
least one pair of terminal members connected to each other, each having
an outer terminal, a lead including an inner terminal, and a die pad by
subjecting a terminal forming sheet to half-etching; mounting a
semiconductor device on the die pad; connecting the inner terminals of
the terminal members of the processed sheet to the semiconductor device
with bond wires; attaching a molding tape to the processed sheet, and
sealing the processed sheet and the semiconductor device in a resin
molding by molding; and finishing a plastic package by removing the
molding tape from the resin molding, attaching a cutting tape to the
resin molding and cutting parts, corresponding to the connection of the
processed sheet, of the resin molding from a side opposite the side of
the cutting tape.

[0073]In the plastic package fabricating method according to the present
invention, the processed sheet and the semiconductor device are held
between a pair of flat plates for molding to seal the processed sheet and
the semiconductor device in the resin molding.

[0074]In the plastic package fabricating method according to the present
invention, the processed sheet and the semiconductor device are enclosed
in a space defined by a flat plate and a predetermined mold for molding
to seal the processed sheet and the semiconductor device in the resin
molding.

[0075]The plastic package of the present invention achieves the further
miniaturization and thickness reduction of semiconductor parts at a low
cost, and enables the efficient mass-production of QFN or SON packages
having high moisture resistance and high heat-dissipating ability.

[0077]A package formed by stacking thin semiconductor chips in a
three-dimensional arrangement and sealing the stacked thin semiconductor
chips in a plastic package can realize a system LSI and can be used as a
system package, such as a system-in-package (SIP).

[0078]The processed sheet is formed by a half-etching process, at least a
thick portion of each of the outer terminals has a thickness equal to
that of the terminal forming sheet, and the terminal member consists of
the outer terminal and the lead including the inner terminal and formed
integrally with the outer terminal. The die pad formed by thinning a
terminal forming sheet by a half-etching process and the semiconductor
device are used, the outer terminals and the inner terminals are formed
such that the upper and lower surfaces of the outer terminals and the
contact surfaces of the inner terminals are included in planes,
respectively, and the terminal members are disposed around the
semiconductor device with the outer terminals extending outward and the
inner terminals extending inward. Surfaces of the leads not half-etched
and the outer side surfaces of the outer terminals are exposed. Surfaces
of the leads not half-etched are exposed, and the outer side surfaces and
the upper surfaces of the outer terminals are partially exposed, and the
rest of the component parts of the plastic package are sealed in the
resin molding.

[0079]Wire bonding for connecting the terminals of the semiconductor
device to the inner terminals facilitates connecting work and ensures the
reliability of connection.

[0080]The plastic package can be efficiently mass-produced by a plastic
package fabricating method of a multiple-chip fabricating system
according to the present invention.

[0081]The plastic package according to the present invention has a flat,
square shape, the surfaces of the leads not half-etched and the outer
side surfaces of the outer terminals are exposed, and the rest of the
component parts of the plastic package are sealed in the resin molding.
The component parts of the plastic package can be simply and
simultaneously sealed in the resin molding by a molding process not using
any special mold. Thus, the construction of the plastic package is
suitable for mass production.

[0082]More specifically, the half-etched surface of the die pad and the
half-etched surfaces of the leads face opposite directions, respectively,
and the surface of the die pad not half-etched and the surfaces of the
outer terminals not etched are included in a plane to facilitate molding
for sealing all the components of the plastic package in the resin
molding simultaneously.

[0083]Since the half-etched surface of the die pad is covered with the
sealing resin, the chip is rarely cracked or chipped, and the sealing
resin improves moisture resistance.

[0084]The positional relation between the die pad and the terminal members
enables mounting a semiconductor device greater than the die pad on the
die pad.

[0085]The surfaces of the terminal members not half-etched and not on the
side of the half-etched surfaces of the leads, and the outer surfaces of
the outer terminals are exposed or the surfaces of the terminal members
not half-etched and not on the side of the half-etched surfaces of the
leads are exposed and the upper surfaces and the outer side surfaces of
the outer terminals are exposed partially to enhance heat dissipation.

[0086]Cut parts formed in the outer side surfaces of the outer terminals
facilitate dicing.

[0087]In the plastic package according to the present invention, the
terminal member are formed of Cu, a Cu-base alloy or a Fe--Ni alloy
containing 42% Ni.

[0088]In the plastic package according to the present invention, the
contact surfaces of the inner terminals and the upper and the lower
surfaces of the outer terminals of the terminal members are coated with a
plated metal layer chosen from a plated solder layer, a plated gold
layer, a plated silver layer, a plated palladium layer and a plated tin
layer. The plated metal layer ensures reliable connection by wire
bonding.

[0089]The plastic package fabricating method of the present invention is
capable of efficiently mass-producing the plastic package of the present
invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0090]FIGS. 1(a) and 1(b) are views illustrating a plastic package in a
first example of a first embodiment according to the present invention;

[0091]FIGS. 2(a) and 2(b) are views illustrating a plastic package in a
second example of the first embodiment;

[0092]FIGS. 3(a) to 3(i) are views illustrating steps of a plastic package
fabricating method in a first example according to the present invention;

[0093]FIGS. 4(a) to 4(j) are views illustrating steps of a plastic package
fabricating method in a second example according to the present
invention;

[0094]FIG. 5 is a sectional view of a stacked plastic package in a first
example according to the present invention;

[0095]FIG. 6 is a sectional view of a stacked plastic package in a second
example according to the present invention;

[0096]FIG. 7 is a sectional view of a stacked plastic package in a third
example according to the present invention;

[0097]FIG. 8 is a sectional view of a stacked plastic package in a fourth
example according to the present invention;

[0098]FIGS. 9(a) to 9(d) are views illustrating the stacked plastic
package in the fourth example;

[0099]FIGS. 10(a) and 10(b) are views of assistance in explaining a dicing
operation using a dicing saw;

[0100]FIGS. 11(a) and 11(b) are views illustrating a plastic package in a
first example of a second embodiment according to the present invention;

[0101]FIGS. 12(a) and 12(b) are views illustrating a plastic package in a
second example of the second embodiment;

[0102]FIGS. 13(a) and 13(b) are views illustrating a plastic package in a
third example of the second embodiment;

[0103]FIGS. 14(a) and 14(b) are views illustrating a plastic package in a
fourth example of the second embodiment;

[0104]FIGS. 15(a) to 15(c) are views illustrating plastic packages in
modifications of the first, the second and the third example;

[0105]FIGS. 16(a) and 16(b) are views illustrating a plastic package in a
fifth example of the second embodiment;

[0106]FIGS. 17(a) and 17(b) are views illustrating a plastic package in a
sixth example of the second embodiment;

[0107]FIGS. 18(a) and 18(b) are views illustrating plastic packages in
modifications of the plastic packages in the fifth and the sixth example,
respectively;

[0108]FIGS. 19(a) to 19(f) are views illustrating steps of a plastic
package fabricating method in an example;

[0109]FIGS. 20(a) to 20(d) are views illustrating steps following the
steps illustrated in FIGS. 19(a) to 19(f);

[0110]FIGS. 21(a) and 21(b) are views of assistance in explaining a dicing
operation using a dicing saw;

[0111]FIGS. 22(a) and 22(b) are views illustrating a plastic package in a
first example of a third embodiment according to the present invention;

[0112]FIGS. 23(a) and 23(b) are views illustrating a plastic package in a
second example of the third embodiment;

[0113]FIGS. 24(a) and 24(b) are views illustrating a plastic package in a
third example of the third embodiment;

[0114]FIGS. 25(a) and 25(b) are views illustrating a plastic package in a
fourth example of the third embodiment;

[0115]FIGS. 26(a) and 26(b) are views illustrating plastic packages in
modifications of the plastic packages in the first and the third example
of the third embodiment, respectively;

[0116]FIGS. 27(a) to 27(d) are views illustrating steps of a plastic
package fabricating method in an example;

[0117]FIGS. 28(a) to 28(d) are views illustrating steps following those
illustrated in FIGS. 27(a) to 27(d); and

[0118]FIGS. 29(a) and 29(b) are views of assistance in explaining a dicing
operation using a dicing saw.

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment

[0119]Preferred embodiments of the present invention will be described
with reference to the accompanying drawings.

[0120]FIG. 1(a) is a partly sectional side elevation of a plastic package
in a first example of a first embodiment according to the present
invention, FIG. 1(b) is a view taken in the direction of the arrow A1 in
FIG. 1(a), FIG. 2(a) is a partly sectional side elevation of a plastic
package in a second example of the first embodiment, FIG. 2(b) is a view
taken in the direction of the arrow B1 in FIG. 2(a), FIG. 3 illustrates
steps of a plastic package fabricating method in a first example
according to the present invention, FIG. 4 illustrates steps of a plastic
package fabricating method in a second example according to the present
invention, FIG. 5 is a sectional view of a stacked plastic package in a
first example, FIG. 6 is a sectional view of a stacked plastic package in
a second example, FIG. 7 is a sectional view of a stacked plastic package
in a third example, FIG. 8 is a sectional view of a stacked plastic
package in a fourth example, FIG. 9(b) is a sectional view of the stacked
plastic package in the fourth example, FIG. 9(a) is a view taken in the
direction of the arrow D1 in FIG. 9(b), FIG. 9(d) is a sectional view of
the stacked plastic package in the fourth example, FIG. 9(c) is a view
taken in the direction of the arrow D2 in FIG. 9(d), and FIG. 10 is a
view of assistance in explaining a dicing operation using a dicing saw.

[0121]FIG. 1(a) is a sectional view taken on the line A2-A3 in
FIG. 1(b), and FIG. 2(a) is a sectional view taken on the line B2-B3 in
FIG. 2(b). In FIGS. 3 to 9, terminals of a semiconductor device are
omitted to facilitate understanding.

[0122]In FIGS. 3(h) and 4(i), double-headed arrows indicate directions in
which a dicing saw is moved.

[0124]FIGS. 1(a) and 1(b) show a plastic package in a first example of the
first embodiment.

[0125]Referring to FIGS. 1(a) and 1(b), the plastic package includes a
plurality of terminal members 1110 each consisting of an outer terminal
1111, an inner terminal 1112 and a connecting part 1113 connecting the
outer terminal 1111 and the inner terminal 1112, a semiconductor device
1120 provided with terminal pads connected to the inner terminals with
bond wires 1130, and a resin molding 1140 sealing the terminal members
1110, the semiconductor device 1120 and the bond wires 1130 therein.

[0126]Each of the outer terminals 1111 has an upper surface 1111a, a lower
surface 1111b and an outer side surface 1111c. Each of the inner
terminals 1112 has a contact surface 1112a to which the bond wire 1130 is
bonded.

[0127]The outer terminals 1111 are connected to external circuits. The
outer terminals 1111 have a thickness equal to that of a terminal forming
sheet 1210. The inner terminals 1112 are connected to the terminals of
the semiconductor device 1120. The inner terminals 1112 are formed by
half-etching the terminal forming sheet 1210 and have a thickness smaller
than that of the terminal forming sheet 1210. The outer terminal 1111 and
the inner terminal 1112 are formed integrally by an etching process to
form the terminal member 1110. The thickness of the semiconductor device
1120 is smaller than that of the terminal-forming sheet 1210. the
terminals 1121 of the semiconductor device 1120 are connected to the
inner terminals 1112 of the predetermined terminal members 1110,
respectively, with the bond wires 1130. The plastic package has a flat,
square shape included in the thickness of the terminal-forming sheet
1210.

[0128]The half-etched surface of the inner terminal 1112 of each terminal
member 1110 is a contact surface 1112a. The terminal members 1110 are
disposed so that the surfaces 1111a and 1111b of the outer terminal 1111,
and the contact surfaces 1112a of the inner terminals 1112 are included
in planes, respectively. The terminal members 1110 are arranged around
the semiconductor device 1120 with the outer terminals 1111 extended
outward and the inner terminals 1112 extended inward. The surfaces 1111a
and 1111b and the outer side surfaces 1111c of the outer terminals are
exposed outside.

[0129]The semiconductor device 1120 is spaced apart from the inner
terminals 1112. The terminal surface of the semiconductor device 1120 on
the side of the terminals 1121 faces the same direction as the
half-etched surfaces of the terminal members 1110. The back surface 1120a
opposite the terminal surface of the semiconductor device 1120 faces the
same direction as the surfaces opposite the half-etched surfaces of the
terminal members 1110. The semiconductor device 1120 is not mounted on a
die pad and the back surface 1120a of the semiconductor device 1120 is
exposed. The semiconductor device 1120 is packaged in a resin molding
1140.

[0130]This plastic package is not provided with any die pad. the back
surface 1120a opposite the terminal surface provided with the terminals
1121 of the semiconductor device 1120 is exposed. All the components of
the plastic package included in the thickness of the terminal-forming
sheet are sealed in the resin molding 1140. The semiconductor device 1120
is thin.

[0131]For example, when the semiconductor device 1120 has a thickness in
the range of 0.025 to 0.1 mm, the thickness of the terminal forming sheet
1210 forming the terminal members 1110 may be 0.2 mm.

[0132]Wire bonding for connecting the terminals facilitates connecting
work and ensures the reliability of connection.

[0133]The plastic package can be efficiently mass-produced by a plastic
package fabricating method of a multiple-chip fabricating system
according to the present invention, which will be described later.

[0134]A molding step for sealing the component parts in the resin molding
does not need any cavity of a special shape. The component parts need to
be held simply between flat plates for molding. Thus, the construction of
the plastic package is desirable from the viewpoint of equipment.

[0135]Materials suitable for forming the terminal members 1110 are Cu, a
Cu-base alloy, or a Fe--Ni alloy containing 42% Ni. Generally, Cu or a
Cu-base alloy is used owing to its high conductivity and desirable
properties.

[0136]The outer side surfaces 1111c of the outer terminals 1111 are the
cut edges of the terminal forming sheet 1210. The surfaces 1111a and
1111b are coated with a connecting plated layer.

[0138]Usually, the resin molding 1140 is formed of an epoxy resin. The
resin molding 1140 may be formed of any suitable resin other than the
epoxy resin.

[0139]A plastic package in a second example of the first embodiment will
be described with reference to FIG. 2.

[0140]The plastic package in the second example, similarly to the plastic
package in the first example, is provided with terminal members 1110
formed by half-etching a terminal forming sheet 1210 and each consisting
of an outer terminal 1111 of a thickness equal to that of the terminal
forming sheet 1210 to be connected to an external circuit, and an inner
terminal 1112 of a thickness smaller than that of the terminal forming
sheet 1210 to be connected to a semiconductor device 1120. The inner
terminal 1112 is formed integrally with the outer terminal 1111. The
semiconductor device 1120 is thinner than the terminal-forming sheet
1210. Terminals 1121 of the semiconductor device 1120 are connected to
the inner terminals 1112 of the predetermined terminal members 1110,
respectively, with bond wires 1130 by wire bonding. Components of the
plastic package are included in the thickness of the terminal-forming
sheet 1210, and the plastic package has a flat, square shape of a
thickness equal to that of the terminal-forming sheet 1210. The terminals
1121 of the semiconductor device 1120, differing from the terminals 1121
of the semiconductor device 1120 of the first example arranged in two
lines as shown in FIGS. 1(a) and 1(b), are arranged in a single line in a
middle part of the upper surface of the semiconductor device 1120.

[0141]The plastic package shown in FIGS. 2(a) and 2(b) is the same in
other respects as the plastic package shown in FIGS. 1(a) and 1(b).

[0142]Although the terminal members 1110 are arranged along the opposite
sides of the semiconductor device 1120 in the plastic package shown in
FIGS. 2(a) and 2(b), the terminal members 1110 may be arranged in any
other suitable arrangement.

[0143]In plastic packages in modifications of the plastic packages in the
first and the second example, a semiconductor device 1120 is provided
with terminal pads 1121 arranged along the four sides of the upper
surface thereof, and terminal members 1110 are arranged along the four
sides of the semiconductor device 1120.

[0144]Four plastic packages of the same size, for example, similar to the
plastic package in the first example shown in FIGS. 1(a) and 1(b) are
stacked up to build a stacked plastic package as shown in FIG. 5.

[0145]Four plastic packages of the same size, for example, similar to the
plastic package in the second example shown in FIGS. 2(a) and 2(b) are
stacked up to build a stacked plastic package as shown in FIG. 6.

[0146]In those stacked plastic packages, the lower surfaces 1111b of the
outer terminals 1111 of the plastic package are connected electrically to
the upper surfaces 1111a of the outer terminals 1111 of the plastic
package underlying the former.

[0147]A stacked plastic package as shown in FIG. 7 may be built by
stacking plastic packages of the same size including those similar to the
plastic package in the first example and those similar to the plastic
package in the second example.

[0148]A stacked plastic package as shown in FIG. 8 may be built by
stacking plastic packages similar to the plastic package in the first
example and those similar to the plastic package in the second example
respectively having different sizes.

[0149]A stacked plastic package as shown in FIGS. 9(a) and 9(b) may be
built by using eight plastic packages 1401 to 1408 of the same size
similar to the plastic package in the first example. The stacked plastic
package is built by stacking four planar combinations of the plastic
packages 1401 to 1408 formed by combining the two symmetrical plastic
packages 1401 and 1405, the two symmetrical plastic packages 1402 and
1406, the two symmetrical plastic packages 1403 and 1407, and the two
symmetrical plastic packages 1404 and 1408 with the corresponding outer
side surfaces 1111c of the outer terminals 1111 electrically connected.

[0150]A stacked plastic package as shown in FIGS. 9(c) and 9(d) may be
built by using eight plastic packages 1501 to 1508 of the same size
similar to the plastic package in the second example. The stacked plastic
package is built by stacking four planar combinations of the plastic
packages 1501 to 1508 formed by combining the two symmetrical plastic
packages 1501 and 1505, the two symmetrical plastic packages 1502 and
1506, the two symmetrical plastic packages 1503 and 1507, and the two
symmetrical plastic packages 1504 and 1508 with the corresponding outer
side surfaces 1111c of the outer terminals 1111 electrically connected.

[0151]The outer side surfaces 1111c of the corresponding outer terminals
1111 are connected electrically with a conductive paste.

[0152]In FIGS. 9(a), 9(b), 9(c) and 9(d), for example, the outer terminals
1111 denoted by {circle around (1)} are power terminals, those denoted by
{circle around (2)} are grounding terminals, those denoted by {circle
around (3)} to {circle around (7)} are I/O terminals and those denoted by
{circle around (8)} are switching terminals. The outer side surfaces
1111c of the outer terminals 1111 are connected properly and the inner
terminals are contended properly to the terminals of the semiconductor
devices by wire bonding to form a desired circuit.

[0153]The number of the stacked combinations of the plastic packages is
not limited to four.

[0154]A composite plastic package may be a planar combination of three
plastic packages similar to the plastic package in the first or the
second example formed by electrically connecting the outer side surfaces
1111c of the outer terminals 1111 thereof. A stacked plastic package may
be built by stacking two or more planar combinations each of three
plastic packages similar to the plastic package in the first or the
second example formed by electrically connecting the outer side surfaces
1111c of the outer terminals 1111 thereof.

[0155]A stacked plastic package may be formed by stacking the plastic
packages and electrically connecting the outer side surfaces 1111c of the
respective outer terminals 1111 of the vertically adjacent plastic
packages.

[0156]A plastic package fabricating method in a first example according to
the present invention will be described with reference to FIG. 3.

[0157]Resist films 1220 respectively having predetermined patterns are
formed on the opposite surfaces of a terminal forming sheet 1210 as shown
in FIG. 3(a). Both the surfaces of the terminal forming sheet 1210 are
etched to form pairs of terminal members 1230 for a plurality of
semiconductor devices as shown in FIG. 3(b). Each pair of terminal
members 1230 are connected by a connecting part 1235.

[0158]Thus, a processed sheet 1210A having the pairs of terminal members
1230 for a plurality of plastic packages is formed. Each pair of terminal
members 1230 has a connecting part 1235 connecting the two terminal
members 1230.

[0159]The terminal forming sheet 1210 is a sheet of Cu, a Cu-base alloy, a
Fe--Ni alloy containing 42% Ni or the like. A ferric chloride solution is
used as an etchant.

[0160]There is not particular restrictions on the resist films 1220,
provided that the resist films 1220 are capable of withstanding the
etching action of the etchant, of being patterned in a desired resolution
and of being easily processed.

[0161]The resist films 1220 are removed from the processed sheet 1210A,
the processed sheet 1210A is subjected to processes including a cleaning
process. Then, the processed sheet 1210A is coated entirely with a plated
layer 1210B for connection. Then, processed sheet 1210A is held on a
perforated suction plate (semiconductor device mounting tape) 1240 by
suction with the lower surface opposite the half-etched upper surface
thereof in close contact with the perforated suction plate 1240 as shown
in FIG. 3(c). Then, a predetermined number of semiconductor devices 1250
are located at predetermined positions, respectively, and are mounted on
the perforated suction plate 1240 by suction with the back surface
opposite the surface provided with terminal pads 1121 in close contact
with the perforated suction plate 1240 as shown in FIG. 3(d). The
semiconductor devices 1250 are held in place on the perforated suction
plate 1240 by suction.

[0162]A suction system including a vacuum pump, a suction pipe and such,
not shown, is connected to the perforated suction plate 1240.

[0163]Then, the terminals 1121 of the semiconductor devices 1250 are
connected to the half-etched contact surfaces of the inner terminals 1112
of the terminal members 1230 with bond wires 1260, respectively, as shown
in FIG. 3(e).

[0164]Then, the processed sheet 1210A is separated from the perforated
suction plate 1240, a molding tape 1270 is attached to the lower surface
opposite the half-etched upper surface of the processed sheet 1210A with
the back surfaces of the semiconductor devices 1250 firmly bonded to the
molding tape 1270. The processed sheet 1210A is held between a pair of
flat molding plates 1270a, and then the processed sheet 1210A held
between the pair of flat molding plates 1270a is sealed in a resin
molding 1280 by molding. Then, the molding plates 1270a are removed as
shown in FIG. 3(f).

[0165]The connecting parts 1235 connecting the terminal members 1230 of
the processed sheet 1210A are provided with through holes. A resin for
forming packages flows through the through holes of the connecting parts
1235 during a molding process.

[0166]Then, the molding tape 1270 is removed from the resin molding 1280,
and a cutting tape 1275 is applied to the resin molding 1280 as shown in
FIG. 3(g). Then, the resin molding 1280 is cut from a side opposite the
side of the cutting tape 1275 with a dicing saw, not shown, as shown in
FIG. 3(h) to obtain individual plastic packages as shown in FIG. 3(i).

[0167]As shown in FIG. 3(h), thin parts of the processed sheet
corresponding to grooves 1237 are cut with the dicing saw.

[0168]The resin molding is cut with the dicing saw, not shown, along
cutting lines, for example, shown in FIG. 10(a) or 10(b).

[0171]The cut surfaces of the processed sheet 1310A are the outer side
surfaces of the outer terminals of the plastic packages.

[0172]Surfaces of the cut parts 1237A other than the cut surfaces are
plated and can be easily used for connection.

[0173]The plastic package in the first example shown in FIG. 1 is thus
fabricated.

[0174]A plastic package fabricating method in another example according to
the present invention will be described with reference to FIG. 4.

[0175]Resist films 1320 respectively having predetermined patterns are
formed on the opposite surfaces of a terminal forming sheet 1310 as shown
in FIG. 4(a). Both the surfaces of the terminal forming sheet 1310 are
etched to form pairs of terminal members 1330 for a plurality of
semiconductor devices as shown in FIG. 4(b). Each pair of terminal
members 1330 are connected by a connecting part 1335.

[0176]Thus, a processed sheet 1310A having the pairs of terminal members
1330 for a plurality of plastic packages is formed. Each pair of terminal
members 1330 has a connection 1335 connecting the two terminal members
1330.

[0177]Then, the resist films 1320 are removed form the processed sheet
1310A, the processed sheet 1310A is subjected to processes including a
cleaning process. Then, the processed sheet 1310A is coated entirely with
a plated layer 1310B for connection. Then, a molding tape (semiconductor
device mounting tape) 1340 is applied to the lower surface opposite the
half-etched upper surface of the processed sheet 1310A as shown in FIG.
4(c). Then, a predetermined number of semiconductor devices 1350 are
located at predetermined positions, respectively, and are mounted on the
mounted on the molding tape 1340 with the back surface opposite the
surface provided with terminal pads 1121 in close contact with the
molding tape 1340 as shown in FIG. 4(d).

[0178]Then, the terminals 1121 of the semiconductor devices 1350 are
connected to the half-etched contact surfaces of the inner terminals 1112
of the terminal members 1330 with bond wires 1360, respectively, as shown
in FIG. 4(e).

[0179]Then, the processed sheet 1310A is held between flat molding plates
1371 and 1372, and the assembly of the processed sheet 1310A and the
semiconductor devices 1350 is sealed in a resin molding 1380 by molding
as shown in FIG. 4(f).

[0180]Then, the molding plates 1371 and 1372 are removed from the resin
molding 1380 as shown in FIG. 4(g). The mounting tape 1340 is removed and
a cutting tape 1345 is applied to the resin molding 1380 as shown in FIG.
4(h). Then, the resin molding 1380 is cut from a side opposite the side
of the cutting tape 1345 with a dicing saw, not shown, as shown in FIG.
4(i) to obtain individual plastic packages as shown in FIG. 3(j).

[0181]The plastic package fabricating method illustrated by FIG. 4 is
basically the same as that illustrated by FIG. 3 in processes and parts
and hence further description thereof will be omitted.

[0182]The plastic package in the first example shown in FIG. 1 can be
fabricated by any one of those plastic package fabricating methods.

[0183]As apparent from the foregoing description, the present invention
provides a thin plastic package suitable for mass production and capable
of being manufactured at a low cost. The present invention provides also
a stacked plastic package built by staking thin plastic packages. Thus,
the so-called stacked system package can be realized. The present
invention provides a plastic package fabricating method of fabricating
such a thin plastic package.

Second Embodiment

[0184]A second embodiment of the present invention will be described.

[0185]FIG. 11(a) is a sectional view of a plastic package in a first
example of a second embodiment according to the present invention, FIG.
11(b) is a view taken in the direction of the arrow A1 in FIG. 11(a),
FIG. 12(a) is a sectional view of a plastic package in a second example
of the second embodiment, FIG. 12(b) is a view taken in the direction of
the arrow B1 in FIG. 12(a), FIG. 13(a) is a sectional view of a plastic
package in a third example of the second embodiment, FIG. 13(b) is a view
take in the direction of the arrow C1 in FIG. 13(a), FIG. 14(a) is a
sectional view of a plastic package in a fourth example of the second
embodiment, FIG. 14(b) is a view take in the direction of the arrow D1 in
FIG. 14(a), FIGS. 15(a), 15(b) and 15(c) are views of plastic packages in
modifications of the first, the second and the third example,
respectively, FIG. 16(a) is a sectional view of a plastic package in a
fifth example of the second embodiment, FIG. 16(b) is a view take in the
direction of the arrow E1 in FIG. 16(a), FIG. 17(a) is a sectional view
of a plastic package in a sixth example of the second embodiment, FIG.
17(b) is a view take in the direction of the arrow F1 in FIG. 17(a),
FIGS. 18(a) and 18(b) are sectional views of plastic packages in
modifications of the plastic packages in the fifth and the sixth example,
respectively, FIG. 19 is sectional views illustrating the steps of
plastic package fabricating method in an example according to the present
invention, FIG. 20 is sectional views illustrating steps following those
illustrated by FIG. 19, and FIG. 21 is a view of assistance in explaining
a dicing operation.

[0186]FIG. 11(a) is a sectional view taken on the line A2-A3 in FIG.
11(b), FIG. 12(a) is a sectional view taken on the line B2-B3 in FIG.
12(b), FIG. 13(a) is a sectional view taken on the line C2-C3 in FIG.
13(b), FIG. 14(a) is a sectional view taken on the line D2-D3 in FIG.
14(b), FIG. 16(a) is a sectional view taken on the line E2-E3 in FIG.
16(b), and FIG. 17(a) is a sectional view taken on the line F2-F3 in FIG.
17(b).

[0187]Double-headed arrows in FIG. 20(c) indicate directions in which a
dicing saw is moved.

[0189]FIGS. 11(a) and 11(b) illustrate a plastic package in a first
example. Referring to FIGS. 11(a) and 11(b), the plastic package has a
plurality of terminal members 2110 consisting of outer terminals 2112,
and leads 2114 including inner terminals 2111, a semiconductor device
2120 provided with terminal pads 2121 connected to the inner terminals
2111 with bond wires 2130, and a resin molding 2140 sealing the terminal
members 2110, the semiconductor device 2120 and the bond wires 2130
therein. Each of the outer terminals 2112 has an upper surface 2112c, a
lower surface 2112a and an outer side surface 2112b. Each of the inner
terminals 2111 has an upper surface 2114b and a lower surface 2114a.

[0190]The outer terminals 2112 to be connected to external circuits, and
the leads 2114 including the inner terminals 2111 to be connected to the
semiconductor device 2120 are connected integrally to form the terminal
members 2110. A terminal forming sheet 2310 is processed by a
half-etching process to form the outer terminals 2112 respectively having
thick portions of a thickness equal to that of the terminal forming sheet
2310, and the leads 2114 thinner than the terminal forming sheet 2310.
The semiconductor device 2120 is of a center-pad type. The terminals
(terminal pads) 2121 of the semiconductor device 2120 are connected to
the inner terminals 2111 of the predetermined terminal members 2110 with
bond wires 2130, respectively. The assembly of the semiconductor device
2120, the terminal members 2110 and the bond wires 2130 is sealed in a
resin to form a flat, square plastic package.

[0191]All the upper surfaces 2112c of the outer terminals 2112, all the
lower surfaces 2112a of the outer terminals 2112, and the etched surfaces
(the lower surfaces of the inner terminals) of the leads 2114a are
included in planes, respectively. The terminal members 2110 are arranged
near the semiconductor device 2120 with the outer terminals 2112
extending outward and the inner terminals 2111 extending inward. The
lower surfaces 2114a of the inner terminals 2111 are etched surfaces
2114a. The plastic package is a LOC (lead-on-chip) plastic package, in
which the semiconductor device 2120 is mounted on the inner terminals
2111 with its terminal surface 2120a in contact with the upper surfaces
2114b of the leads 2114 opposite the half-etched surfaces 2114a, i.e.,
the upper surfaces of the inner terminals 2111. The lower surfaces 2112a
(contact surfaces 2112a) of thick portions of the outer terminals 2112 on
the side of the half-etched surfaces 2114a of the terminal members 2110,
and the outer side surfaces 2112b (contact surfaces 2112b) of the outer
terminals 2112 are exposed outside, and the rest of the component parts
are sealed in the resin molding 2140.

[0192]The plastic package in the first example can be formed in a small
thickness by sealing the component parts including the semiconductor
device 2120 in the resin molding 2140 such that the surfaces of the
terminal members 2110 corresponding to the lower surface of the terminal
forming sheet 2310 are exposed outside.

[0193]The plastic package can be formed in a small thickness by using a
thin semiconductor device as the semiconductor device 2120.

[0194]The thickness of the plastic package in this example is equal to the
sum of the respective thicknesses of the terminal forming sheet 2310 and
the semiconductor device 2120.

[0195]Wire bonding for connecting the terminals of the semiconductor
device 2120 to the inner terminals 2111 facilitates connecting work and
ensures the reliability of connection.

[0196]The plastic package can be fabricated by a plastic package
fabricating method of a multiple-chip fabricating system, which will be
described later and is suitable for mass production.

[0197]A molding step for sealing the component parts in the resin molding
2140 does not need any cavity of a special shape. The component parts
need to be held simply between flat plates for molding. Thus, the
construction of the plastic package is desirable from the viewpoint of
equipment.

[0198]Materials suitable for forming the terminal members 2110 are Cu, a
Cu-base alloy, or a Fe--Ni alloy containing 42% Ni. Generally, Cu or a
Cu-base alloy is used owing to its high conductivity and desirable
properties.

[0199]The outer side surfaces 2112b of the outer terminals 2112 are the
cut edges of the terminal forming sheet 2310, and the other surfaces of
the outer terminals 2112 are coated with a connecting plated layer.

[0201]Usually, the resin molding 2140 is formed of an epoxy resin. The
resin molding 2140 may be formed of any suitable resin other than the
epoxy resin.

[0202]A plastic package in a second example of the second embodiment will
be described with reference to FIG. 12.

[0203]The plastic package in the second example, similarly to the plastic
package in the first example, is provided with terminal members 2110
formed by half-etching a terminal forming sheet 2310 and each consisting
of an outer terminal 2112 to be connected to an external circuit, and
leads 2114 including inner terminals 2111 to be connected to a
semiconductor device 2120. Each external terminal 2112 has a thick
portion of a thickness equal to that of the terminal forming sheet 2310,
and the leads 2114 are formed by thinning portions of the terminal
forming sheet 2310 by half-etching. Terminals 2121 of the semiconductor
device 2120 are connected to the inner terminals 2111 of the
predetermined terminal members 2110, respectively, with bond wires 2130
by wire bonding. Those component parts including the semiconductor device
2120 are sealed in a resin molding 2140 to form a flat, square plastic
package. All the upper surfaces 2112c of the outer terminals 2112, all
the lower surfaces 2112a of the outer terminals 2112, and all the etched
surfaces 2114a of the leads 2114 of the terminal members 2110 are
included in planes, respectively. The terminal members 2110 are arranged
near the semiconductor device 2120 with the inner terminals 2112
extending inward.

[0204]The contact surfaces of the inner terminals 2111 of the plastic
package in the second example, differing from those of the plastic
package in the first example, are in a surface 2114b opposite the etched
surfaces (the lower surfaces of the inner terminals) 2114a. The plastic
package in the second example is a LOC (lead-on-chip) plastic package, in
which the semiconductor device 2120 is mounted on the leads 2114 with its
terminal surface 2120a in contact with the half-etched surfaces 2114a of
the leads 2114.

[0205]The lower surfaces 2112a of the thick portions of the outer
terminals on the side of the half-etched surface 2114a and the outer side
surfaces 2112b of the outer terminals of the terminal members 2110 are
exposed outside. The rest of the component parts are sealed in the resin
molding 2140.

[0206]The plastic package in the second example can be formed in a small
thickness by sealing the component parts including the semiconductor
device 2120 in the resin molding 2140 such that the surfaces of the
terminal members 2110 corresponding to the surface of the terminal
forming sheet 2310 are exposed outside.

[0207]The thickness of the semiconductor device 2120 is smaller than a
depth in which the terminal forming sheet 2310 is etched to form the
terminal members 2110.

[0208]When the thickness of the terminal forming sheet 2310 for forming
the terminal members 2110 is, for example, 0.2 mm, the thickness of the
semiconductor device 2120 is in the range of 0.025 to 0.1 mm.

[0209]Wire bonding for connecting the terminals of the semiconductor
device 2120 to the inner terminals 2111 facilitates connecting work and
ensures the reliability of connection.

[0210]Although the position of the semiconductor device 2120 relative to
the leads 2114 in the plastic package in the second example is different
from that in the plastic package in the first example, the plastic
package in the second example can be fabricated by a plastic package
fabricating method of a multiple-chip forming system basically similar to
the plastic package fabricating method of fabricating the plastic package
in the first example. The plastic package in the second example is
suitable for mass production.

[0211]A molding step for sealing the component parts of the plastic
package in the second example in the resin molding 2140, similarly to
that for sealing the component parts of the plastic package in the first
example in the resin molding 2140, does not need any cavity of a special
shape. The component parts need to be held simply between flat plates for
molding. Thus, the construction of the plastic package is desirable from
the viewpoint of equipment.

[0212]The component parts of the plastic package in the second embodiment
are the same as those of the plastic package in the first example.

[0213]A plastic package in a third example will be described with
reference to FIG. 13.

[0214]A plastic package in the third example is formed by mounting a
semiconductor device 2125 of a peripheral-pad type (additional
semiconductor device) on a surface of the semiconductor device 2120
opposite a terminal surface 2120a of the plastic package in the first
example. The semiconductor device 2125 is provided with terminal pads
2126 on a surface opposite a surface thereof facing the semiconductor
device 2120. The terminals 2126 of the semiconductor device 2125 are
connected to leads 2114 by wire bonding.

[0215]The component parts of the plastic package in the third example,
similarly to those of the plastic package in the first embodiment, are
sealed in a resin molding such that the surfaces of terminal members 2110
corresponding to one of the surfaces of a terminal forming sheet 2310 are
exposed outside. Therefore, the plastic package can be formed in a small
thickness even though the semiconductor devices 2120 and 2125 are
stacked.

[0216]Although the plastic package is provided with the two semiconductor
devices 2120 and 2125, the plastic package can be fabricated by a plastic
package fabricating method of a multiple-chip system basically the same
as that of fabricating the plastic package in the first example. The
molding step of the plastic package fabricating method of fabricating the
plastic package in the third example, similarly to that of fabricating
the plastic package in the first example, does not need any cavity of a
special shape. The component parts of the plastic package held simply
between flat plates can be easily sealed in the resin molding by the
molding step, which is desirable from the viewpoint of equipment.

[0217]The component parts of the plastic package in the third example are
the same as those of the plastic package in the first example.

[0218]A plastic package in a fourth example will be described with
reference to FIG. 14.

[0219]A plastic package in the fourth example is similar to that in the
third example. The plastic package in the fourth example is formed by
mounting a semiconductor device 2125A of a peripheral-pad type provided
with terminal pads arranged along the four sides thereof on a surface of
a semiconductor device 2120A of a center-pad type, and arranging terminal
members 2110 along the four sides of the semiconductor devices 2120A and
2125A.

[0220]The terminals 2126A of the semiconductor device 2125A are connected
to the surfaces 2114b of leads 2114 with bond wires 2135A.

[0221]The component parts of the plastic package in the fourth example,
similarly to those of the plastic package in the first embodiment, are
sealed in a resin molding such that the surfaces of terminal members 2110
corresponding to one of the surfaces of a terminal forming sheet 2310 are
exposed. Therefore, the plastic package can be formed in a small
thickness.

[0222]Although the plastic package is provided with the two semiconductor
devices 2120A and 2125A, the plastic package can be fabricated by a
plastic package fabricating method of a multiple-chip system basically
the same as that of fabricating the plastic package in the first example.
The molding step of the plastic package fabricating method of fabricating
the plastic package in the fourth example, similarly to that of
fabricating the plastic package in the first example, does not need any
cavity of a special shape. The component parts of the plastic package
held simply between flat plates can be easily sealed in the resin molding
by the molding step, which is desirable from the viewpoint of equipment.

[0223]The component parts of the plastic package in the fourth example are
the same as those of the plastic package in the first example.

[0224]FIGS. 15(a), 15(b) and 15(c) show plastic packages in modifications
of the plastic packages in the first, the second and the third example,
respectively. The plastic packages in those modifications differ from
those in the first, the second and the third example in that the lower
surfaces 2112a on the side of a half-etched surface of thick parts of
outer terminals 2112 of terminal members 2110 are used as contact
surfaces, and part of the outer side surfaces 21112b and the upper
surfaces 2112c of the outer terminals 2112 of the terminal members are
exposed to use the same as terminals.

[0225]A plastic package in a modification of the plastic package in the
fourth example may be similar in construction as those modifications of
the plastic packages in the first, the second and the third example.

[0226]A plastic package in a fifth example will be described with
reference to FIG. 16.

[0227]A plastic package in the fifth example is provided with terminal
members 2210 similar to those of the plastic package in the first
example, and a semiconductor device 2220 of a peripheral-pad type
provided with terminal pads 2221 arranged along the four sides thereof.
The terminals 2221 of the semiconductor device 2220 are connected to the
inner terminals 2211 of the predetermined terminal members 2210,
respectively with bond wires 2230.

[0228]The upper surfaces 2212c and the lower surfaces 2212a of the outer
terminals 2212 of the terminal members 2210, and etched surfaces 2214a of
leads 2214 are included in planes, respectively. The terminal members
2210 are arranged around the semiconductor device 2220 with the outer
terminals 2212 extending outward and the inner terminals 2211 extending
inward. The contact surfaces of the inner terminals 2211 are in a plane
opposite the etched surfaces 2214a of leads 2214. The semiconductor
device 2220 is mounted on the leads 2214 of the terminal members 2210
with a peripheral part of its lower surface opposite its terminal surface
2220a on which the terminals 2221 are arranged in contact with the leads
2214 to form a COL structure (chip-on-lead structure).

[0229]The component parts of the plastic package, similarly to those of
the plastic package in the first example, are sealed in a resin molding
with the back surfaces 2212a, on the half-etched surfaces 2214a of the
terminal members 2210, of thick parts and outer side surfaces 2212b of
the outer terminals 2212, i.e., contact surfaces 2212a and 2212b,
exposed.

[0230]The component parts excluding the semiconductor device 2220 are the
same as those of the plastic package in the first example. The plastic
package in the fifth example, similarly to that in the first example, is
suitable for mass production and can be fabricated by a plastic package
fabricating method of a multiple-chip fabricating system. The molding
step of the plastic package fabricating method of fabricating the plastic
package in the fifth example, similarly to that of fabricating the
plastic package in the first example, does not need any cavity of a
special shape. The component parts of the plastic package held simply
between flat plates can be easily sealed in the resin molding by the
molding step, which is desirable from the viewpoint of equipment.

[0231]The component parts of the plastic package in the fifth example are
the same as those of the plastic package in the first example.

[0232]A plastic package in a sixth example will be described with
reference to FIG. 17.

[0233]The plastic package in the sixth example is formed by mounting a
semiconductor device 2225 of a peripheral-pad type on the terminal
surface 2220a of a semiconductor device 2220. The semiconductor device
2225 is provided with terminal pads 2226 on a surface opposite a surface
thereof facing the semiconductor device 2220. The terminal pads 2226 of
the semiconductor device 2225 are connected to leads 2114 by wire
bonding.

[0234]The component parts of the plastic package in the sixth example,
similarly to those of the plastic package in the first embodiment, are
sealed in a resin molding such that the surfaces of terminal members 2110
corresponding to one of the surfaces of a terminal forming sheet 2310 are
exposed. Therefore, the plastic package can be formed in a small
thickness even though the semiconductor devices 2220 and 2225 are
stacked.

[0235]The plastic package in the sixth example provided with the two
semiconductor devices, similarly to that in the first example, is
suitable for mass production and can be fabricated by a plastic package
fabricating method of a multiple-chip fabricating system. The molding
step of the plastic package fabricating method of fabricating the plastic
package in the sixth example, similarly to that of fabricating the
plastic package in the first example, does not need any cavity of a
special shape. The component parts of the plastic package held simply
between flat plates can be easily sealed in the resin molding by the
molding step, which is desirable from the viewpoint of equipment.

[0236]The component parts of the plastic package in the sixth example are
the same as those of the plastic package in the first example.

[0237]Resin moldings included in plastic packages shown in FIGS. 18(a) and
18(b) in modifications of the plastic packages in the fifth and the sixth
example are somewhat different from those included in the plastic
packages in the fifth and the sixth example. As shown in FIGS. 18(a) and
18(b), the component parts of each of the plastic packages in the
modifications are sealed in a resin molding 2240 such that the lower
surfaces 2212a, on the side of a half-etched surface, of thick parts, the
outer side surfaces 2212b and portions of the upper surfaces 2212c of the
external terminals 2212 of terminal members 2210, i.e., contact surfaces,
are exposed.

[0238]A plastic package fabricating method of fabricating the plastic
package in the first example will be described with reference to FIGS. 19
and 20.

[0239]Resist films 2320 respectively having predetermined patterns are
formed on the opposite surfaces of a terminal forming sheet 2310 as shown
in FIG. 19(a). Both the surfaces of the terminal forming sheet 2310 are
etched to form pairs of terminal members 2330 for a plurality of
semiconductor devices as shown in FIG. 19(b). Each pair of terminal
members are connected by a connection 2336.

[0240]Thus, a processed sheet 2310A having the pairs of terminal members
2330 for a plurality of plastic packages is formed.

[0241]The terminal forming sheet 2310 is a sheet of Cu, a Cu-base alloy, a
Fe--Ni alloy containing 42% Ni or the like. A ferric chloride solution is
used as an etchant.

[0242]There is not particular restrictions on the resist films 2320,
provided that the resist films 2320 are capable of withstanding the
etching action of the etchant, of being patterned in a desired resolution
and of being easily processed.

[0243]The resist films 2320 are removed from the processed sheet 2310A as
shown in FIG. 19(c), the processed sheet 2310A is subjected to processes
including a cleaning process. Then, the processed sheet 2310A is coated
entirely with a plated layer 2310B for connection. Then, a predetermined
number of semiconductor devices 2340 are located at predetermined
positions, respectively, and are mounted on the leads 2337 of terminal
members 2330 as shown in FIG. 19(d).

[0244]Then, the terminal pads 2341 of the semiconductor devices 2340 are
connected to the half-etched contact surfaces of the inner terminals 2111
of the terminal members 2330 with bond wires 2350, respectively, as shown
in FIG. 19(e).

[0245]Then, a molding tape 2360 is attached to the half-etched surface
2337a of the processed sheet 2310A as shown in FIG. 19(f).

[0246]Then, the processed sheet 2310A is held between a pair of flat
molding plates 2371 and 2372, and then the processed sheet 2310A held
between the pair of flat molding plates 2371 and 2372 is sealed in a
resin molding 2380 by molding as shown in FIG. 20(a).

[0247]The connections 2336 connecting the terminal members 2330 of the
processed sheet 2310A are provided with through holes. A resin for
forming packages flows through the through holes of the connections 2336
during a molding process.

[0248]Thus, the plastic package in the first example shown in FIG. 11 is
fabricated.

[0249]The molding plates 2371 and 2372 are removed, and then the molding
tape 2360 is removed as shown in FIG. 20(b). Then, a cutting tape 2365 is
applied to the resin molding 2380 as shown in FIG. 20(c).

[0250]Then, the resin molding 2380 is cut from a side opposite the side of
the cutting tape 2365 with a dicing saw, not shown, to obtain individual
plastic packages as shown in FIG. 20(d).

[0251]The resin molding 2380 is cut with the dicing saw, not shown, along
cutting lines, for example, shown in FIG. 21(a) or 21(b).

[0254]The cut surfaces of the processed sheet 2310A are the outer side
surfaces of the outer terminals of the plastic packages.

[0255]Surfaces of the cut parts 2334A other than the cut surfaces are
plated and can be easily used for connection.

[0256]The plastic package in the first example shown in FIG. 11 is thus
fabricated.

[0257]Although the plastic packages in the second to the sixth example
differ from each other in the positional relation between the
semiconductor device and the leads of the terminal members, in the step
of stacking the semiconductor devices or the step of electrically
connecting the semiconductor device and the terminal members by wire
bonding, plastic package fabricating methods for fabricating those
plastic packages are substantially similar to that for forming the
plastic package in the first example.

[0258]In the plastic packages, shown in FIG. 15, in modifications of the
first example and the plastic packages in the fifth and the sixth example
shown in FIG. 18, the lower surfaces, on the side of the half-etched
surfaces of the terminal members, of the thick parts of the outer
terminals are exposed, and the outer side surfaces and the upper surfaces
of the outer terminals of the terminal members are partially exposed, and
the rest of the component parts are sealed in the resin molding. The
component parts can be sealed in the resin molding by putting a flat
plate 2371 on one side of the assembly of the component parts so as to
cover the contact surfaces, to be exposed, of the external terminals, and
putting a mold 2372a on the other side of the assembly of the component
parts to form a predetermined cavity after mounting the plurality of
semiconductor devices on the leads and connecting the semiconductor
devices to the corresponding inner terminals by wire bonding by the
plastic package fabricating method as mentioned in connection with FIGS.
19 and 20, and pouring the resin in the cavity.

[0259]For example, a mold capable of forming a cavity for sixteen plastic
packages in a region G as shown in FIG. 21(a) is used, and a molding
process is repeated for regions G.

[0260]As apparent from the foregoing description, the present invention
achieves the further reduction of the thickness of plastic packages at a
low cost and provides plastic packages suitable for mass production. The
present invention achieves the reduction of the thickness of the QFN or
the SON package provided with a semiconductor device of a center-pad
type. The present invention provides a plastic package fabricating method
of fabricating such a thin plastic package.

Third Embodiment

[0261]A third embodiment of the present invention will be described with
reference to the accompanying drawings.

[0262]FIG. 22(a) is a sectional view of a plastic package in a first
example of a third embodiment according to the present invention, FIG.
22(b) is a view taken in the direction of the arrow A1 in FIG. 22(a),
FIG. 23(a) is a sectional view of a plastic package in a second example
of the second embodiment, FIG. 23(b) is a view taken in the direction of
the arrow B1 in FIG. 23(a), FIG. 24(a) is a sectional view of a plastic
package in a third example of the third embodiment, FIG. 24(b) is a view
take in the direction of the arrow C1 in FIG. 24(a), FIG. 25(a) is a
sectional view of a plastic package in a fourth example of the third
embodiment, FIG. 26(b) is a view take in the direction of the arrow D1 in
FIG. 25(a), FIGS. 26(a) and 26(b) are views of plastic packages in
modifications of the first and the third example, respectively, FIG. 27
is sectional views illustrating some of the steps of a plastic package
fabricating method in an example according to the present invention, FIG.
28 is sectional views illustrating steps following those illustrated by
FIG. 27, and FIG. 29 is a view of assistance in explaining a dicing
operation.

[0263]FIG. 22(a) is a sectional view taken on the line A2-A3 in FIG.
22(b), FIG. 23(a) is a sectional view taken on the line B2-B3 in FIG.
23(b), FIG. 24(a) is a sectional view taken on the line C2-C3 in FIG.
24(b), and FIG. 25(a) is a sectional view taken on the line D2-D3 in FIG.
25(b).

[0264]Double-headed arrows in FIG. 28(c) indicate directions in which a
dicing saw is moved.

[0266]Referring to FIGS. 22(a) and 22(b), a plastic package in a first
example has a plurality of terminal members 3110 consisting of outer
terminals 3111, and leads 3114 including inner terminals 3112, a die pad
3150 connected to the terminal members 3110, a semiconductor device 3120
mounted on the die pad 3150 and provided with terminal pads 3121
connected to the inner terminals 3112 with bond wires 3130, and a resin
molding 3140 sealing the terminal members 3110, the die pad 3150, the
semiconductor device 3120 and the bond wires 3130 therein. Each of the
outer terminals 3111 has an upper surface 3117a, a lower surface 3117 and
an outer side surface 3118. Each of the inner terminals 3112 has a
contact surface 3114a.

[0267]The outer terminals 3111 to be connected to external circuits, and
the leads 3114 including the inner terminals 3112 to be connected to the
semiconductor device 3120 are connected integrally to form the terminal
members 3110. A terminal forming sheet 3210 is processed by a
half-etching process to form the outer terminals 2112 respectively having
thick portions of a thickness equal to that of the terminal forming sheet
3210, and the leads 3114 thinner than the terminal forming sheet 3210.
The die pad 3150 is formed by thinning a portion of the terminal forming
sheet 3210 by half etching. The semiconductor device 3210 is of a
peripheral-pad type. The terminal pads 3210 of the semiconductor device
3120 are arranged along two opposite sides of the semiconductor device
3120. The terminal pads 3121 of the semiconductor device 3120 are
connected to the inner terminal pads 3121 of the predetermined terminal
members 3110 with bond wires 3130, respectively. The assembly of the
semiconductor device 3210, the terminal members 3110 and the bond wires
3130 is sealed in a resin to form a flat, square plastic package. The
terminal members 3110 are arranged along two opposite sides of the
semiconductor device 3120 to form a SON package.

[0268]All the upper surfaces 3117a of the outer terminals 3111, all the
lower surfaces 3117 of the outer terminals 3111, and the contact surfaces
(the etched surfaces) 3114a of the inner terminals 3112 of terminal
members 3110 are included in planes, respectively. The terminal members
3110 are arranged near the semiconductor device 3120 with the outer
terminals 3111 extending outward and the inner terminals 3112 extending
inward. The half-etched surface of the die pad 3150 and the half-etched
surfaces 3114a of the leads face opposite directions, respectively. The
nonetched surface 3150b of the die pad 3150, and the nonetched surfaces
(upper surfaces) 3117a of the outer terminals 3111 on the side of the
half-etched surface 3114a of the terminal members 3110 are included in a
plane.

[0269]The terminal surface 3120a of the semiconductor device 3120 and the
half-etched surfaces 3114a of the terminal members 3110 face the same
direction. The lower surface 3120b of the semiconductor device 3120 is in
contact with the nonetched surface 3150b of the die pad 3150. The
half-etched surfaces 3114a of the leads 3114 are the contact surfaces of
the inner terminals 3112. The nonetched surfaces 3117, opposite the
half-etched surfaces 3114a, of the leads 3114, and the outer side
surfaces 3118 of the outer terminals 3111 are exposed outside, and the
rest of the component parts are sealed in the resin molding 3140. Each of
the nonetched surfaces 3117 forms the respective lower surfaces of the
outer terminal and the lead 3114.

[0270]The semiconductor device 3120 is greater than the die pad 3150.

[0271]The plastic package in the first example can be formed in a small
thickness by sealing the component parts in the resin molding 3140 such
that the surfaces of the terminal members 3110 corresponding to a
surface, forming the nonetched surfaces 3117, of the terminal forming
sheet 3210 are exposed outside.

[0272]The plastic package can be formed in a small thickness by using a
thin semiconductor device as the semiconductor device 3120.

[0273]The thickness of the plastic package is equal to the sum of the
respective thicknesses of the terminal forming sheet 3210 and the
semiconductor device 3120.

[0274]Wire bonding for connecting the terminals of the semiconductor
device to the inner terminals facilitates connecting work and ensures the
reliability of connection.

[0275]The plastic package can be efficiently mass-produced by a plastic
package fabricating method of a multiple-chip fabricating system
according to the present invention.

[0276]A molding step for sealing the component parts in the resin molding
does not need any cavity of a special shape. The component parts need to
be held simply between flat plates for molding. Thus, the construction of
the plastic package is desirable from the viewpoint of equipment.

[0277]Materials suitable for forming the terminal members 1110 are Cu, a
Cu-base alloy, or a Fe--Ni alloy containing 42% Ni. Generally, Cu or a
Cu-base alloy is used owing to its high conductivity and desirable
properties.

[0278]The outer side surfaces 3118 of the outer terminals 3111 are the cut
edges of the terminal forming sheet 3210. Other surfaces are coated with
a connecting plated layer.

[0280]Usually, the resin molding 3140 is formed of an epoxy resin. The
resin molding 3140 may be formed of any suitable resin other than the
epoxy resin.

[0281]A plastic package in a second example will be described with
reference to FIG. 23.

[0282]Referring to FIG. 23, the plastic package in the second example is
provided with terminal members 3110 formed by integrally connecting outer
terminals 3111 to be connected to external circuits, and leads 3114
including inner terminals 3112 to be connected to a semiconductor device
3120A. The terminal members 3110 are formed by processing a terminal
forming sheet 3210 by a half-etching process. Each of the outer terminals
3111 has at least a thick portion of a thickness equal to that of the
terminal forming sheet 3210. The leads 3114 are formed by thinning
portions of the terminal forming sheet 3210 by a half-etching process. A
die pad 3150 is formed by thinning a portion of the terminal forming
sheet 3120 by a half-etching process. A semiconductor device 3120A of a
peripheral-pad type provided with terminal pads 3121 arranged along the
four sides thereof. The semiconductor device 3120a is mounted on the die
pad 3150, and the terminal pads 3121 of the semiconductor device 3120A
are connected to the inner terminals 3112 of the predetermined terminal
members 3110, respectively, with bond wires 3130. Those component parts
are sealed in a resin molding 3140 to form a flat, square plastic
package. The plastic package in the second example is a QFN package in
which the terminal members 3110 are arranged along the four sides of the
semiconductor device 3120A.

[0283]In the plastic package in the second example, the terminal members
are arranged along the four sides of the semiconductor device 3120A.

[0284]The component parts and construction of the plastic package in the
second example, excluding the arrangement of the terminal members 3110
and the semiconductor device 3120A, are the same as those of the plastic
package in the first example.

[0285]The nonetched surface 3117, on a side opposite the half-etched
surfaces 3114a of the leads 3114, of the terminal members 3110, and the
outer side surfaces 3118 of the outer terminals 3111 are exposed, and the
rest of the component parts are sealed in the resin molding 3140. Thus,
the plastic package can be formed in a small thickness.

[0287]Wire bonding for connecting the terminal pads 3121 of the
semiconductor device 3120A to the 3112 facilitate connecting work and
ensures the reliability of connection.

[0288]The plastic package in the second example, similarly to that in the
first example, is suitable for mass production and can be fabricated by a
plastic package fabricating method of a multiple-chip fabricating system.

[0289]The molding step of the plastic package fabricating method of
fabricating the plastic package in the second example, similarly to that
of fabricating the plastic package in the first example, does not need
any cavity of a special shape. The component parts of the plastic package
held simply between flat plates can be easily sealed in the resin molding
3140 by the molding step, which is desirable from the viewpoint of
equipment.

[0290]The component parts of the plastic package in the second example are
the same as those of the plastic package in the first example.

[0291]A plastic package in a third example will be described with
reference to FIG. 24.

[0292]The plastic package in the third example, similarly to the plastic
package in the first example, is provided with terminal members 3110
formed by integrally connecting outer terminals 3111 to be connected to
external circuits, and leads 3114 including inner terminals 3112 to be
connected to semiconductor devices 3125 and 3125A of a peripheral-pad
type respectively provided with terminal pads 3126 and 3126A arranged
along the two opposite sides thereof. The terminal members 3110 are
formed by processing a terminal forming sheet 3210 by a half-etching
process. Each of the outer terminals 3111 has at least a thick portion of
a thickness equal to that of the terminal forming sheet 3210. The leads
3114 are formed by thinning portions of the terminal forming sheet 3210
by a half-etching process. A die pad 3150 is formed by thinning a portion
of the terminal forming sheet 3120 by a half-etching process. The
semiconductor devices 3125 and 3125A are stacked on the die pad 3150, the
terminal pads 3126 and 3126A are connected to the inner terminals 3112 of
the predetermined terminal members 3110 with bond wires 3135 and 3135A,
and those component parts are sealed in a resin molding 3140 to form a
SON plastic package.

[0293]All the upper surfaces 3117a of the outer terminals 3111, all the
lower surfaces 3117 of the outer terminals 3111, and the contact surfaces
3114a of the inner terminals 3112 of the terminal members 3110 are
included in planes, respectively. The terminal members 3110 are arranged
near the semiconductor devices 3125 and 3125A with the outer terminals
3111 extending outward and the inner terminals 3112 extending inward. The
half-etched surface 3150a of the die pad 3150 and the half-etched
surfaces 3114a of the leads 3114 face opposite directions, respectively.
The nonetched surface 3117 of the leads 3114 and the nonetched surfaces
3117 of the outer terminals 3111 are included in a plane.

[0294]In the plastic package in the third example, the terminal surface
3125a of the semiconductor device 3125 seated on the die pad 3150, and
the half-etched surface 3114a of the terminal members 3110 face the same
direction. the lower surface 3125b of the semiconductor device 3125 is in
contact with the nonetched surface 3150b of the die pad 3150. The
semiconductor device 3125A is mounted on the terminal surface 3125a of
the semiconductor device 3125 seated on the die pad 3150.

[0295]The half-etched surfaces 3114a of the leads 3114 of the terminal
members 3110 are the contact surfaces of the inner terminals 3112. The
nonetched surfaces 3117, opposite the half-etched surfaces 3114a, of the
leads 3114, and the outer side surfaces 3118 of the outer terminals 3111
are exposed, and the rest of the component parts are sealed in the resin
molding 3140.

[0296]The terminal pads 3126 and 3126A of the semiconductor devices 3125
and 3125A are connected to the etched surfaces 3114a of the leads 3114 of
the terminal members 3110.

[0297]In the plastic package in the third example, a surface of a terminal
member forming sheet 3210, namely, a surface forming the nonetched
surfaces 3117, is exposed outside. Thus, the plastic package provided
with the two stacked semiconductors can be formed in a small thickness.

[0298]The plastic package in the third example provided with the two
semiconductor devices 3125 and 3125A, similarly to the plastic package in
the first example, can be efficiently mass-produced by a plastic package
fabricating method of a multiple-chip fabricating system.

[0299]A molding step for sealing the component parts in the resin molding
does not need any cavity of a special shape. The component parts need to
be held simply between flat plates disposed on the opposite sides of the
stacked semiconductor devices 3125 and 3125A for molding. Thus, the
construction of the plastic package is desirable from the viewpoint of
equipment.

[0300]The component parts of the plastic package in the third example are
similar to those of the plastic package in the first example.

[0301]A plastic package in a fourth example will be described with
reference to FIG. 25.

[0302]The plastic package in the fourth example, similarly to the plastic
package in the first example, is provided with terminal members 3110
formed by integrally connecting outer terminals 3111 to be connected to
external circuits, and leads 3114 including inner terminals 3112 to be
connected to a semiconductor devices 3128 and 3128A. The terminal members
3110 are formed by processing a terminal forming sheet 3210 by a
half-etching process. Each of the outer terminals 3111 has at least a
thick portion of a thickness equal to that of the terminal forming sheet
3210. The leads 3114 are formed by thinning portions of the terminal
forming sheet 3210 by a half-etching process. A die pad 3150 is formed by
thinning a portion of the terminal forming sheet 3120 by a half-etching
process. The semiconductor devices 3128 and 3128A of a peripheral-pad
type are provided with terminal pads 3129 and 3129A arranged along the
four sides thereof. The semiconductor devices 3128 and 3128A are stacked
on the die pad 3150, and the terminal pads 3129 and 3129A of the
semiconductor devices 3128 and 3128A are connected to the inner terminals
3112 of the predetermined terminal members 3110, respectively, with bond
wires 3138 and 3138A. Those component parts are sealed in a resin molding
3140 to form a QFN plastic package.

[0303]The plastic package in the fourth example is provided with the
semiconductor devices 3128 and 3128A provided with the terminal pads
arranged along the four sides thereof instead of the semiconductor
devices 3125 and 3125a of a peripheral-pad type provided with terminal
pads arranged along the two opposite sides thereof, and the terminal
members 3110 are arranged along the four sides of the semiconductor
devices 3128 and 3128A.

[0304]The respective terminal pads 3129 and 3129A of the semiconductor
devices 3128 and 3128A are connected to the etched surfaces 3114a of the
leads 3114 of the terminal members 3110, respectively.

[0305]In the plastic package in the fourth example, a surface of the
terminal forming sheet 3210, i.e., the nonetched surface 3117, similarly
to that of the plastic package in the first example, is exposed. Thus,
the plastic package in the fourth example can be formed in a small
thickness.

[0306]The plastic package in the fourth example provided with the two
semiconductor devices, similarly to that in the first example, is
suitable for mass production and can be fabricated by a plastic package
fabricating method of a multiple-chip fabricating system. The molding
step of the plastic package fabricating method of fabricating the plastic
package in the fourth example, similarly to that of fabricating the
plastic package in the first example, does not need any cavity of a
special shape. The component parts of the plastic package held simply
between flat plates can be easily sealed in the resin molding by the
molding step, which is desirable from the viewpoint of equipment.

[0307]The component parts of the plastic package in the fourth example are
similar to those of the plastic package in the first example.

[0308]Resin moldings included in plastic packages in modifications of the
plastic packages in the first and the third example are somewhat
different from those included in the plastic packages in the first and
the third example. As shown in FIGS. 26(a) and 26(b), the component parts
of each of the plastic packages in the modifications are sealed in a
resin molding 3140 such that the nonetched surfaces 3117, i.e., surfaces
opposite half-etched surfaces 3114a, of leads 3114, outer side surfaces
3119 of outer terminals 3111, and portions of the upper surfaces 3117a of
the outer terminals 3111 are exposed.

[0309]Plastic packages in modifications of the plastic packages in the
second and the fourth example are similar to those plastic packages.

[0310]Plastic packages in modifications of the plastic packages in the
third and the fourth example are provided with semiconductor devices of a
center-pad type instead of the semiconductor device 3125A of the third
example and the semiconductor device 3128A of the fourth example,
respectively.

[0311]The plastic package in the third example may be provided with three
or more stacked semiconductor devices instead of the semiconductor
devices 3125 and 3125A, the plastic package in the fourth example may be
provided with three or more stacked semiconductor devices instead of the
semiconductor devices 3128 and 3128A, and those semiconductor devices may
be connected to the internal terminals of the predetermined terminal
members by wire bonding.

[0312]In the plastic packages in those modifications, a semiconductor
device of a peripheral-pad type is seated on the die pad with its
terminal surface facing a direction in which the half-etched surfaces of
the terminal members face, and the lower surface thereof in contact with
the nonetched surface of the die pad, and the semiconductor devices
excluding the top semiconductor device are of a peripheral-pad type, and
those semiconductor devices are stacked one on top of another on the
semiconductor device mounted on the die pad.

[0313]A plastic package fabricating method of fabricating the plastic
package in the first example in an example will be described with
reference to FIGS. 27 and 28.

[0314]Resist films 3220 respectively having predetermined patterns are
formed on the opposite surfaces of a terminal forming sheet 3210 as shown
in FIG. 27(a). Both the surfaces of the terminal forming sheet 3210 are
etched to form pairs of terminal members 3230 for a plurality of
semiconductor devices as shown in FIG. 27(b). Each pair of terminal
members are connected by a connecting part 3236.

[0315]Thus, a processed sheet 3210A having the pairs of terminal members
3230 each connected by the connecting part 3236 for a plurality of
plastic packages is formed.

[0316]The terminal forming sheet 3210 is a sheet of Cu, a Cu-base alloy, a
Fe--Ni alloy containing 42% Ni or the like. A ferric chloride solution is
used as an etchant.

[0317]There is not particular restrictions on the resist films 3220,
provided that the resist films 3220 are capable of withstanding the
etching action of the etchant, of being patterned in a desired resolution
and of being easily processed.

[0318]The resist films 3220 are removed form the processed sheet 3210A as
shown in FIG. 27(c), the processed sheet 3210A is subjected to processes
including a cleaning process. Then, the processed sheet 3210A is coated
entirely with a plated layer 3210B for connection. Then, a predetermined
number of semiconductor devices 3250 are located at predetermined
positions on a surface, opposite a half-etched surface 3234a, of the
processed sheet 3210A, respectively, and are mounted on die pads 3240,
respectively. Then the terminal pads 3251 of the semiconductor devices
3250 are connected to the contact surfaces, i.e., the half-etched
surfaces 3114a, of inner terminals 3112 of the terminal members 3230 with
bond wires 3260 as shown in FIG. 27(d).

[0319]Then, a molding tape 3280 is attached to the half-etched surface
3234a of the processed sheet 3320A. Then, the processed sheet 3320A is
held between a pair of flat molding plates 3271 and 3272, and then the
processed sheet 3210A held between the pair of flat molding plates 3271
and 3272 is sealed in a resin molding 3290 by molding as shown in FIG.
28(a).

[0320]The connections 3236 connecting the terminal members 3230 of the
processed sheet 3210A are provided with through holes. A resin for
forming packages flows through the through holes of the connecting parts
3236 during a molding process.

[0321]The molding plates 3271 and 3272 are removed, and then the molding
tape 3280 is removed as shown in FIG. 28(b). Then, a cutting tape 3285 is
applied to the resin molding 3290 as shown in FIG. 28(c). Then, the resin
molding 3290 is cut from a side opposite the side of the cutting tape
3285 with a dicing saw, not shown, to obtain individual plastic packages
as shown in FIG. 28(d).

[0322]The resin molding 3290 is cut with the dicing saw, not shown, along
cutting lines, for example, shown in FIG. 29(a) or 29(b).

[0325]The cut surfaces of the processed sheet 3210A are the outer side
surfaces 3238 of the outer terminals of the plastic packages.

[0326]Surfaces of cut parts 3235A other than the cut surfaces are plated
and can be easily used for connection.

[0327]The plastic package in the first example shown in FIG. 22 is thus
fabricated.

[0328]Although the plastic packages in the second to the fourth example
differ from each other in the positional relation between the
semiconductor device and the leads of the terminal members, in the step
of stacking the semiconductor devices or the step of electrically
connecting the semiconductor device and the terminal members by wire
bonding, plastic package fabricating methods for fabricating those
plastic packages are substantially similar to that for forming the
plastic package in the first example.

[0329]In each of plastic packages shown in FIG. 26 in modifications of the
plastic packages in the first and the third example, nonetched surfaces
3117, surfaces opposite the half-etched surfaces 3114a of the leads 3114,
side surfaces 3119 of outer terminals 3111 of terminal members 3110, and
portions of the upper surfaces 3117a of the outer terminals 3111 are
exposed, and the rest of the component parts are sealed in a resin
molding. This resin molding can be formed by the plastic package
fabricating method illustrated in FIGS. 27 and 28; the component parts
can be sealed in the resin molding by mounting a semiconductor device
3120 (semiconductor devices 3125 and 3125A) on a die pad 3150, connecting
the semiconductor device 3120 (the semiconductor devices 3125 and 3125A)
to terminal members 3110 with bond wires 3130 (bond wires 3135 and
3135A), attaching a flat plate 3272 to the lower surfaces, on one side of
the assembly of the component parts, of the terminal members 3110, and
putting a mold 3271a on the other side of the assembly of the component
parts to form a predetermined cavity, and pouring the resin in the
cavity.

[0330]For example, a mold capable of forming a cavity for sixteen plastic
packages in a region G as shown in FIG. 29(a) is used, and a molding
process is repeated for regions G.

[0331]Although plastic packages in other modifications need a step of
stacking semiconductor devices and an additional wire bonding step, those
plastic packages can be fabricated by plastic package fabricating methods
substantially similar to those for fabricating the plastic packages shown
in FIG. 26 in modifications of the plastic packages in the first and the
third example.

[0332]As apparent from the foregoing description, the present invention
achieves the further miniaturization and reduction of the thickness of
plastic packages at a low cost and provides QFN OR SON plastic packages
suitable for mass production and having high moisture resistance and high
heat-dissipating ability. The present invention provides stacked QFN or
SON packages. The present invention provides plastic package fabricating
methods of fabricating such thin plastic packages.

Patent applications by Chikao Ikenaga, Shinjuku-Ku JP

Patent applications by Masachika Masuda, Shinjuku-Ku JP

Patent applications by DAI NIPPON PRINTING CO., LTD.

Patent applications in class With structure for mounting semiconductor chip to lead frame (e.g., configuration of die bonding flag, absence of a die bonding flag, recess for LED)

Patent applications in all subclasses With structure for mounting semiconductor chip to lead frame (e.g., configuration of die bonding flag, absence of a die bonding flag, recess for LED)